I’m interested in crafting some very dense, subharmonic sounds, and being new to sound design I was wondering if anyone would be able to give me a few pointers on how to approach this area of interest.

Since I'm new to this forum I'm unable to post links. The following two tracks illustrate the kind of sound I'm after:

Regis - Blood Witness
Porter Ricks - Biokinetics 2

By no means do I expect any easy answers here. I understand that crafting audio takes work and creativity. I’m just looking for a bit of guidance from potentially experienced individuals to point me in the right direction.

The Porter Ricks example sounds like a self oscillating filter being moved about a bit.general things that will introduce sub-harmonics (as in harmonics below a fundamental and not just like in your Porter Ricks example which is just sub )Amplitude Modulation,anything that will introduce DC,ACTUAL FM,recording incidentals like handling noise,dropping mics,leaving mics near certain kinds of electrical appliances,Convoluting sounds with acoustic kick drums and floor toms..that's all i have for now